This invention relates to an apparatus for compacting coal in a pounding box by alternately raising and releasing punners so that they can drop onto the coal and compact it into a cake for use in coking ovens.
More particularly, the invention relates, in an apparatus of this type, to the means for raising the punners.
Certain types of hard coal are suited for coking operations only if the coal has first been compacted to form a coke which is then inserted into the coking oven. The compacting is carried out in a pounding box into which a quantity of coal is admitted. To obtain economical operation, it is necessary that compacting of the coal charge in the pounding box be effected as rapidly as possible; at the same time, however, the compaction must be as effective and as uniform as possible throughout the entire volume of the pounding box.
Compacting is carried out by punners which are each composed of an upright carrying a foot at its lower end. The punners are raised and then released to drop onto the coal under the influence of gravity. To obtain the desired results each punner must perform a large number of drops per unit time; it must also be raised as high as possible to obtain sufficient impact and it must be raised to substantially the same height every time.
Once the coal has been sufficiently compacted to form a cake, the punners must be retained in their raised position so as to disengage their feet from the cake, in order to permit the cake to be pushed into the coking oven.
The prior-art constructions are not fully satisfactory in connection with these operations. They do not raise the punners uniformly or to sufficient heights and may, over a period of time, even undergo sufficient wear so that they do not raise the punners at all. Moreover, they use rotating discs which are to raise the punners and which produce highly objectionable noise levels when the equipment is in operation.
When the compaction process is finished, the punners of the prior-art equipment are maintained in raised positions by manually hammering-in wedges which engage the uprights and hold them in upper positions. This is time-consuming and ultimately damages the uprights where they are engaged by the wedges. Moreover, this method is not reliable because the wedges frequently work loose -- or are not applied sufficiently strongly to hold the punners in place.